Two hundred thousand people turned out in Rio de Janeiro urging the president to throw out a new law they believe will cost their region dear.

It is intended to share the country’s oil wealth more evenly throughout Brazil, and as one of the biggest oil producing states, Rio believes it will lose billions at a time when they are spending billions on showpiece sporting events.

One protester said: “The new way of sharing oil royalties makes managing Rio de Janeiro state non-viable at a time where it is showing not only socio-economic growth but also a series of opportunities for foreign investment, particularly the World Cup and Olympics.”

Another protester, Carlos Lima, said: “Taking away royalties means the states and cities that produce oil will go bankrupt.”

It is a tough choice for President Dilma Rousseff, who has promised to reduce poverty levels partly by redistributing windfalls from commodities like oil and minerals.

It is possible she could partly veto the bill, blocking the sections that deal with royalties for existing oil-producing states and cities.